Barack Obama waits seconds before being introduced at his swearing-in ceremony at the US Capitol in Washington on 20 January 2009.
Photograph: Pete Souza / White House Photo / HO/EPA

2008

5 November

Barack Obama makes history by becoming the first African American to win the US presidency.

With the promise of “hope and change”, he enters the White House as America is fighting wars in Iraq and Afghanistan. At home, the US faces the worst financial crisis since the Great Depression of the 1930s.

Barack Obama with his wife and daughters, Malia and Sasha, on election night on 4 November 2008. Photograph: Jae C Hong/AP

2009

22 January

The new president promises to close Guantánamo Bay, the contentious US facility in Cuba used to detain terror suspects, many of whom are held without charge. To this day, it remains open.

17 February

Obama signs a huge $787bn (£548bn) stimulus bill designed to save and create thousands of jobs to boost the beleaguered US economy.

18 February

A surge in violence in Afghanistan sees Obama pledge an extra 17,000 military personnel, doubling the US presence there. Days later he promises to end to the war in Iraq: “Let me say this as plainly as I can: by August 31, 2010, our combat mission in Iraq will end.”

31 March

Obama flies into London for the G20 summit where talks about the global financial crisis dominate. He meets the British prime minister, Gordon Brown, and other world leaders. The president and his wife also meet the Queen. Leaving the UK, Obama visits Turkey, where he says: “The United States is not, and will never be, at war with Islam.”

30 July

The president tries to act as peacemaker by holding a “beer summit” at the White House with a black Harvard professor arrested for alleged disorderly conduct outside his home in Massachusetts and the white police officer who took him in.

The Guardian publishes details of 250,000 American diplomatic cables, some marked “secret” or “confidential”, from the WikiLeaks whistleblowing website. In response, the White House says: “President Obama supports responsible, accountable and open government at home and around the world, but this reckless and dangerous action runs counter to that goal.” The founder of WikiLeaks, Julian Assange, says the US authorities were afraid of being held to account.

18 December

The Arab Spring begins. Obama later pays tribute to the uprisings in the Middle East and North Africa as “a moment of opportunity” for change in the region.

2011

19 March

The UK, US and France attack Muammar Gaddafi’s forces in Libya to enforce a UN-mandated no-fly zone. The “worst mistake” of his presidency is how Obama described his lack of support to Libya after Gaddafi was deposed.

Osama bin Laden, the world’s most wanted man, is killed by US special forces in a night-time raid of his secret compound in Abbottabad, Pakistan. Obama and his top advisers watch a live feed of the mission from the White House Situation Room.

Barack Obama, vice-president Joe Biden, secretary of state Hillary Clinton and members of the national security team receive an update on the mission against Osama bin Laden. Photograph: Pete Souza/AP

15 December

Obama formally declares that the Iraq war is over and that the US is to pull out. In a speech at Fort Bragg, North Carolina, the president is careful not to say the US won the nine-year conflict.

2012

26 February

The fatal shooting of Trayvon Martin, an unarmed black teenager, in Florida by an armed neighborhood-watch volunteer prompts Obama to say: “If I had a son, he’d look like Trayvon.” The man who shot Martin is found not guilty of second-degree murder and acquitted of manslaughter, a lesser charge. But some protesters claim Martin was only stopped because of racial profiling.

The Democratic party convention in Charlotte backs Obama as nominee for the 2012 presidential race but some delegates express disappointment about his first term.

6 November

Obama’s popularity may have slipped but he wins re-election, beating Republican challenger Mitt Romney. In his victory speech, he says: “I have never been more hopeful about America. And I ask you to sustain that hope.”

14 December

Obama wipes away his tears when addressing the nation about the 20 children and six adults who died in a mass shooting at Sandy Hook elementary school in Newtown, Connecticut. Promising “meaningful action”, he also says: “As a country, we have been through this too many times.”

Barack Obama pauses to wipe a tear as he speaks about the shooting at Sandy Hook elementary school in Newtown, Connecticut. Photograph: Yuri Gripas/Reuters

2013

2 January

A compromise bill pushed through by Obama prevents the US falling off the “fiscal cliff” – a set of scheduled tax rises and sharp spending cuts likely to trigger a new recession.

21 March

Warning about the use of chemical weapons, Obama tells Syria’s Assad regime that there is a “red line” that must not be crossed.

15 April

Three people are killed after two brothers plant homemade pressure cooker bombs near the finishing line of the Boston Marathon. One of the bombers is killed when cornered by police, the other captured and put on trial – he is found guilty and sentenced to death in 2015.

5 June

The Guardian publishes leaked documents from whistleblower Edward Snowden about the clandestine activities of the US National Security Agency, for whom he had previously worked. In what is regarded as one of the most significant leaks in American political history, Snowden has evidence that the NSA maintained a number of mass surveillance programmes over its own citizens, including accessing information stored by some of the country’s biggest technology companies. Responding, Obama says: “You can’t have 100% security, and also then have 100% privacy and zero inconvenience.”

Speaking about the death toll of Ebola victims climbing to 4,500 since an outbreak in west Africa, Obama says the US must respond much more aggressively to prepare at home and confront the outbreak abroad.

2015

The New York Times reveals that Hillary Clinton, when serving as Obama’s secretary of state, broke official rules by using a personal email instead of a government one for official correspondence. Clinton would continue to be dogged by the revelation.

2016

22 April

At a joint press conference with the prime minister, David Cameron, in London, Obama warns the British public that a vote to leave the EU could put the UK at the “back of the queue” when negotiating trade deals with the US.

Obama suffers the humiliation of having Congress override his veto for the first time. The president tried to block a law that allowed 9/11 families to sue Saudi Arabia for its alleged role in the September 11 attacks.

The US abstains from voting in a UN Security Council resolution that declares Israeli settlements in Palestinian territory illegal. Previously, the US could always be counted on to veto such a bill.

28 December

Obama designates two new national monuments, protecting over 150m acres of land, including sacred Native American sites, in Nevada and Utah. During Obama’s presidency, he has federally protected over 550m acres with his executive powers.